While plague cures were varied and steeped in superstition, most people knew about the symptoms of the plague. The plague that hit England in 1665 was the bubonic plague and as early as 1353, Boccaccio wrote about the classic symptoms associated with the Bubonic Plague:
“The first sign of the plague was that swellings appeared in the groin or the armpits. Some of the swellings became as large as an apple, sometimes they were the size of an egg. The deadly swellings then began to spread in all directions over the body. Then the disease changed. Black or red spots broke out, sometimes on the thigh or arm. These spots were large in some cases; in other they were almost like a rash.”
A few days after being infected, a victim developed a rash and there was pain all over the body. The victim began to feel tired and lethargic but the pain made it difficult to sleep. The temperature of the body increased and this affected the brain and the nerves. Speech was affected and the victims became less and less intelligible. As the disease took more of a hold, the victim took on the physical appearance of a drunk with stumbling movement and gait. The victim then became delirious.
After about six days, the lymphatic glands became swollen and inflamed. In the groin, neck and armpit areas of the body this led to buboes – large and highly painful swellings. These buboes caused bleeding underneath the skin, which turned the buboes and surrounding areas blue/purple. In some cases, red spots appeared on the buboes as death approached.
The average time of death from the first symptom was between four to seven days. It is thought that between 50% and 75% of those who caught the disease died.
"Symptoms of the Plague". HistoryLearningSite.co.uk. 2007. Web.